Trimmer head with pivot posts holding a single strip of line

ABSTRACT

A fixed-line trimmer head for a rotary trimmer device includes the upper portion having a periphery, wherein the upper portion has a plurality of openings spaced from the periphery; and a plurality of mechanisms. Each mechanism can hold a strip of line and includes a post portion disposed through one of the openings in the upper portion, and a flange disposed at one end of the post portion and sandwiched between the upper portion and lower portion of the trimmer head to prevent vertical movement of the mechanism. The post portion includes two line channels, each line channel defining a passageway to receive the same strip of line, wherein at least one of the line channels is curved such that any portion of the strip of line being received through the passageway of that line channel is bent at that portion of the strip of line away from the second line channel while passing through that at least one line channel that is curved.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a division of U.S. application Ser. No. 14/731,895,filed Jun. 5, 2015, which claims the benefit of U.S. Provisional PatentApplication No. 62/008,366, filed Jun. 5, 2014, the which applicationsare incorporated herein by reference.

FIELD

The present invention relates generally to trimmer heads for rotarytrimmers using monofilament line as a means for cutting vegetation. Moreparticularly, the invention relates to trimmer heads with an improvedmeans to hold single strips of trimmer line, the means being capable ofpivoting to minimize line breakage upon impact with solid objects anddense vegetation.

BACKGROUND

Vegetation trimming devices are well known and are commonly used tomaintain one's lawn and garden. There are a number of differentclassifications of rotary trimmer heads, defined generally by the mannerin which a monofilament trimmer line is fed, spooled or replaced in thetrimmer head and/or how the trimmer line is discharged, indexed orlengthened during use of the trimmer head. Such classifications include(a) “self-indexing” trimmer heads, wherein trimmer line is automaticallyreleased from a spool inside the trimmer head upon a determination ofincreased rotational speed of the trimmer head, (b) “bump-fed” or“bump-activated” trimmer heads, wherein trimmer line is mechanicallyreleased from a spool inside the trimmer head by the user “bumping” thebump knob or similar member on the ground so as to permit a length ofline to be released, and (c) “fixed-line” trimmer heads, wherein alength of line is introduced and loaded or otherwise attached manuallythrough spaced openings usually, but not always, at the periphery of thetrimmer head into a line-holding mechanism that holds the trimmer lineto the trimmer head during use, eliminating the need for a spool. Thepresent invention is directed to a special type of these “fixed-line”trimmer heads.

The majority of aftermarket trimmer heads sold are (c) “fixed-line”trimmer heads because they are easily designed to be universallyadaptable to essentially any brand of rotary trimmer regardless of theoperation of the trimmer head or the direction of rotation. Replacementstrips of trimmer line used for this type of trimmer head are typicallyabout 8 to 15 inch in length and can be easily added to the head througheither openings at the periphery or within the line-holding mechanismsemployed. Generally, fixed-line trimmer heads use a base portion havinga series of radially spaced line holders, each capable of holding onestrip of trimmer line. After the line strip wears, the consumer manuallyremoves the used strip. Once the old worn length of line is removed, anew length of trimmer line can be loaded into the line holdingmechanism. There is no indexing or lengthening of the line during use.The ease-of-use has been a reason for the market acceptance of this typeof trimmer head. However, the need for improvement still exists for thistype of trimmer head.

There are a variety of methods and mechanisms developed and discussed inthe prior art for holding a fixed length of trimmer line to a trimmerhead. Among the more popular methods for holding strips of line include(i) means for holding one end of a single strip of line such that oneend is held by and within the trimmer head, while the other end impactsand cuts vegetation, (ii) means disposed within the trimmer head housingfor holding the strip of line in the middle such that both distal endsextend from the trimmer head for impacting and cutting vegetation, and(iii) means for holding a folded strip of line outside of, and typicallyabove, the trimmer head such that both ends of the strip of line impactsor cuts vegetation. Since the present invention is focused on improvingfixed-line trimmer heads that employ line-holding mechanisms similar tothose used to hold folded strips of line (i.e., method (iii) above), butwith certain modifications, the prior art and problems associated withthese line-holding mechanisms for folded strips of line are furtherdiscussed.

U.S. Pat. Nos. 7,603,782 and 7,743,511, the disclosures of which areincorporated herein by reference, disclose trimmer heads with variousline holding mechanisms for holding folded strips of line. Unlike theother types of “fixed line” trimmer heads, the strips of line areattached to the line-holding mechanism outside of the trimmer headhousing. That is, the line is attached to the line-holding mechanismabove or below the trimmer head housing. Furthermore, the line-holdingmechanism is capable of pivoting on a vertical axis for the purpose ofreducing stress on the line, not for any purpose related to theclamping, or otherwise holding, of the line.

While there are several mechanisms disclosed for holding folded stripsof line, the most commercialized of these line holding mechanisms isdisclosed in the '511 patent, wherein the line-holding mechanisms havethe basic shape of a round post with a flange at the lower end. The topend is beveled (slanted) on two opposite sides with two straight-throughpassageways for insertion of the trimmer line as best seen in FIG. 19 ofthe '511 patent. The flange is sandwiched between a lower cover and theupper portion of the head and is held such that it can rotate about avertical axis but cannot be move vertically. The pivot posts oncommercial trimmer heads are injection molded as a single piece ofplastic and have two straight, parallel through holes or line channelswith a portion of plastic separating the two through holes or linechannels.

To load the trimmer line into the trimmer head, two opposed ends of afolded strip of line are threaded through the two straight parallelholes till the central folded portion of line is pulled tightly againstthe portion of plastic separating the two holes. Typically, this is doneby loading one end of the folded strip of line through an entrance toone of the parallel, straight through line channels and simultaneouslyor in series, loading the other end of the folded strip of line throughan entrance to the other of the parallel, straight through linechannels, which entrance is adjacent the first line channel. The foldedstrip is then pulled tight until the folded central portion of the stripof line disposed against the portion of plastic separating the two linechannels. Commercial trimmer heads utilizing this type pivoting lineholding mechanism can have two, three or four pivoting posts and arecommercially available from various commercial outlets and manufacturersunder the tradenames PivoTrim® X2, PivoTrim®, the PivoTrim® Classic andPivoTrim® Pro, wherein PivoTrim is a registered trademark of BetterHeads, LLC of Pearland, Tex., and Ugly Head®, wherein Ugly Head is aregistered trademark of Shakespeare Company, LLC, of Columbia, S.C.,respectively.

During use, the trimmer head is rotated by a trimming device such as aweed trimmer machine or brush cutter. The ends of each folded piece oftrimmer line will extend out radially beyond the periphery of thetrimmer head due to the centrifugal force created by the rotation of thetrimmer head. The tips of the trimmer line are able to cut vegetationdue to their velocity, due to rotation of the trimmer head. However, ifthe trimmer line impacts an immovable object or very dense vegetation,the line and post can pivot away from the point of impact, which reducesthe stress on the trimmer line.

Unfortunately, line drag has been found to be problem with this type of“fixed line” trimmer head. Because each line in the prior art for thistype of “fixed line” trimmer head is folded in half to form an extended“U”, each line is, in actuality, two lines cutting essentially the samevegetation at or near the same place relative to the trimmer head. Ifthere four radially spaced line-holding mechanisms on a trimmer head, itwill be appreciated that there are no fewer than eight extended lines,two for each line-holding mechanism, given that folded strips of lineare required wherein the extended lengths from the fold to the end ofthe line are essentially equal in length. It has been found that, onceone of the lines cuts the vegetation, the second line is not needed andonly serves to slow the velocity of the tips of the lines due to winddrag. Further, it is also possible that the second line cuts vegetationthat is already cut by the first line, again causing a reduction in thevelocity of the entire line. Cutting vegetation that is already cut doesnot serve any identifiable purpose.

Thus, the need exists for a “fixed-line” trimmer head having a pivotingline-holding mechanism of the type similar to that used for foldedstrips of line, but which is capable of holding line that will lessenthe drag upon the use of the line.

Because the present invention involves “fixed-line” trimmer heads forholding single strips of line in combination with pivoting mechanisms,the prior art with respect to this concept is also addressed.Specifically, both Iacona U.S. Pat. No. 7,257,898 and Aliss U.S. Pat.No. 8,307,558 teach methods for holding single strips of trimmer line incombination with pivoting posts. However, both of these mechanismsinvolve adding components, such as clamps and springs, to the internalportion of the pivoting mechanism. As a result, the housing of themechanism must be enlarged to make room for the extra components. Thismakes the overall mechanism larger in size and adds weight. Theincreased weight from the larger post mechanisms and the addedcomponents is affected by the centrifugal force generated by therotation velocity of the trimmer head. This increased outwardcentrifugal force increases the resistance to pivoting of the mechanismdue to friction between the mechanism and the opening in the trimmerhead. Thus, it is more difficult for the line-holding mechanism topivot.

Likewise, the energy to pivot the line-holding mechanism is reduced dueto the reduction from two legs to one leg of trimmer line extending fromthe trimmer head. The line, being operatively connected to the pivotmechanism, when impacted by an immovable object provides the energy torotate the line-holding mechanism in one direction so that the linemoves away from the object. The centrifugal force acting on the linethen provides the energy to rotate the mechanism in the seconddirection. The centrifugal force makes the line pivot until it reachesan outward radial position. The amount of centrifugal force is dependenton the rotational speed and the mass of line. By reducing the number ofend lengths extending from the mechanism from two per mechanism to oneper mechanism, the centrifugal force is reduced in half. The energyassociated with this reduced centrifugal force must overcome theincreased frictional resistance associated with the heavier pivot post.

Thus, the need exists for a “fixed-line” trimmer head having a pivotingline-holding mechanism of the type similar to that used for foldedstrips of line, but which is capable of holding line that will lessenthe drag upon the use of the line and which does not increase the weightof the line-holding mechanism.

SUMMARY

At least one or more of the foregoing aspects of the present invention,together with the advantages thereof over the known art relating tofixed-line trimmer heads, which shall become apparent from thespecification and drawings that follows, may be accomplished by theinvention as hereinafter described and claimed.

Generally, and as noted above, the present invention relates to afixed-line type of trimmer head of the type that employs line-holdingmechanism similar to those used for holding folded strips of line.However, in those fixed line trimmer heads, both ends of the foldedstrip of line is used to cut vegetation. In this invention, theline-holding mechanisms have been designed to hold a single strip ofline, not a centrally-folded strip of line, above the housing of thetrimmer heard in a manner where one end of the strip of line is lengthyenough to extend beyond the periphery of the trimmer head so as toimpact and cut vegetation, while the other end of the strip of line isshorter and displaced from being parallel to the other end of the stripof line like in a folded strip of line. Thus, the other end of the stripof line does not extend beyond the periphery of the trimmer head housingand does not cut vegetation.

One aspect of this invention may be achieved by a fixed-line trimmerhead for a rotary trimmer device to be utilized with two or more stripsof line. The trimmer head includes a housing operatively attachable tothe rotary trimmer device, the housing being rotatable when in usearound a central axis of rotation. The housing includes an upper portionand a lower portion extending radially from the central axis, the upperportion having a periphery. The upper portion has a plurality ofopenings spaced from the periphery. The fixed-line trimmer head furtherincludes a plurality of mechanisms, each mechanism being pivotablearound a vertical axis and adapted to hold a strip of line. Themechanism includes a post portion disposed through one of the openingsin the upper portion of the housing, and a flange disposed at one end ofthe post portion and sandwiched between the upper portion and lowerportion to prevent vertical movement of the mechanism. The post portionincludes two unobstructed line channels, each line channel defining apassageway adapted to receive the same strip of line. At least one ofthe line channels is curved such that any portion of the strip of linecapable of being received through the passageway of that line channel isbent at that portion of the strip of line away from the second linechannel while passing through that at least one line channel that iscurved.

In one or more embodiments of the invention, both line channels of eachpost portion are curved such that any portions of a strip of linecapable of being received through the passageways of either of thoseline channels are bent at those portions of the strip of line whilepassing through the line channels. In one or more of these embodiments,both line channels have an entrance and an exit, wherein the entrance ofone line channel faces opposite the exit of the other line channel onthe post portion of the mechanism. In one or more of these embodiments,both line channels are transverse to the vertical axis of the mechanism.In one or more other of these embodiments, the line channels areparallel to the vertical axis of the mechanism. In one or more of theseembodiments, the exit of the one line channel is adjacent to theentrance of the other line channel, with the exit of the one linechannel being proximate to its entrance and the entrance of the otherline channel being proximate to its exit. In one or more otherembodiments the exit of the one line channel is adjacent to the entranceof the other line channel at the end of the post portion opposite theflange, where the exit of the one line channel is proximate to itsentrance and the entrance of the other line channel is proximate to itsexit.

In one or more other embodiments of the invention, one of the two linechannels of a mechanism is straight such that any portion of the stripof line capable of being received through the passageway of that linechannel is not bent at that portion of the strip of line while passingthrough that line channel. Of course, the other of the line channels iscurved as described above. In one or more of these embodiments, bothline channels are transverse to the vertical axis of the mechanism. Inone or more other of these embodiments, both line channels are parallelto the vertical axis of the mechanism. Again, one or more embodiments ofthe invention may have an exit of one line channel that is adjacent toand parallel with the entrance of the other line channel, while theentrance of the one line channel is spaced from and not parallel to theexit of the other line channel. In one or more embodiments, the exit ofthe other of the line channels is disposed through the end of the postportion opposite the flange.

In one or more embodiments, the present invention provides an embodimentof the fixed-line trimmer head as described above, in combination with aplurality of strips of line adapted to cut vegetation. Each strip ofline is held to the trimmer head by one of the plurality of mechanismsand is received through all of the passageways defined by the two linechannels on the mechanism. One end of the strip of line is distal fromthe mechanism and extends beyond the periphery of the upper portion ofthe housing of the trimmer head to cut vegetation, while the other endof the strip of line is proximate to the mechanism and does not extendbeyond the periphery of the upper portion of the housing of the trimmerhead. In the manner, it will be appreciated that the strips of line willcause less drag to the trimmer head than previously provided to trimmerheads that used folded trimmer line wherein both ends of the foldedstrip of line was used to cut vegetation.

Another aspect of this invention may be achieved by a mechanism to beutilized for holding a strip of line. The mechanism includes a postportion; and a flange disposed at one end of the post portion andextending beyond the periphery of the post portion. The post portionincludes two unobstructed line channels. Each line channel defines apassageway adapted to receive the strip of line, and at least one of theline channels is curved such that any portion of the strip of linecapable of being received through the passageway of that line channel isbent at that portion of the strip of line away from the second linechannel while passing through the at least one line channel that iscurved.

In one or more embodiments, both line channels are curved such that anyportion of the line capable of being received by the line channels mustbe bent at those portions while passing through the line channels. Inother embodiments, one line channel is straight such that any portion ofthe strip of line capable of being received by that line channel is notbent at that portion of the strip of line while passing through thatline channel, while the other line channel is curved.

In embodiments where both line channels are curved, further embodimentsinclude both line channels having an entrance and an exit, wherein theentrance of one line channel faces opposite the exit of the other linechannel on the post portion of the mechanism. In some of the sameembodiments, the exit of one line channel is adjacent to the entrance ofthe other line channel, where the exit of the one line channel isproximate to its entrance and the entrance of the other line channel isproximate to its exit. In embodiments where one line channel is straightand the other line channel is curved, both line channels have anentrance and an exit, with the exit of one of the line channel beingadjacent to and parallel with the entrance of the other line channel,while the entrance of the one line channel is spaced from and notparallel to the exit of the other line channel.

Advantageously, it will be appreciated that, by providing a pivotingmechanism suitable for use in holding a strip of line such that one endof the strip of line may extend beyond, by as much as 7 to 15 inches,the periphery of the trimmer head while the other end of the strip ofline does not extend beyond the periphery of the trimmer head, only halfthe amount of line is used to cut vegetation when the trimmer head isrotated as compared to trimmer heads that use folded strips of line,wherein both ends of the folded strips of line extend beyond theperiphery of the trimmer head. Because less line use used, there issignificantly less drag on the trimmer head by the line as compared toprior art trimmer heads using mechanisms for holding folded strips ofline. Additionally, because the means to fix the line to the mechanismdoes not require internally embedded biased clamps, the weight of themechanism is minimized and, hence, pivots more freely. Lastly, theproposed embodiments of this invention are unique in that one distal endof the line is available for trimming vegetation, whereas the seconddistal end exits the mechanism either opposite or orthogonal (i.e.,approximately 90 or 180 degrees) to the other portion of the lineexiting the line-holding mechanism. This angular difference keeps theconsumer from being confused as to how to load the line.

For a fuller understanding of the nature and advantages of the presentinvention, reference should be made to the ensuing detailed descriptionand accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an embodiment of a prior art trimmerhead commercially available and based upon U.S. Pat. No. 7,743,511 (“theJerez patent”);

FIG. 2 is a perspective view of an embodiment of a prior artline-holding mechanism as used in the commercially available trimmerhead of FIG. 1 and based upon the Jerez patent;

FIG. 3 is a rear elevational view of the prior art line-holdingmechanism of FIG. 3 taken from a different perspective to show the otherside of the mechanism;

FIG. 4 is a perspective view of a first embodiment of a line-holdingmechanism according to the concepts of the present invention;

FIG. 5 is another perspective view of the line-holding mechanism of FIG.4;

FIG. 6 is a perspective view of the line-holding mechanism of FIG. 4,having a strip of line loaded therein;

FIG. 7 is a perspective view of a second embodiment of a line-holdingmechanism according to the concepts of the present invention;

FIG. 8 is a perspective view of the line-holding mechanism of FIG. 7,having a strip of line loaded therein;

FIG. 9 is a perspective view of a third embodiment of a line-holdingmechanism according to the concepts of the present invention, with stripof line loaded therein;

FIG. 10 is a perspective sectional view of the line-holding mechanism ofFIG. 9, having a strip of line loaded therein;

FIG. 11 is a perspective sectional view of the same line-holdingmechanism of FIG. 10, without the strip of line present;

FIG. 12 is a perspective view of a fourth embodiment of a line-holdingmechanism according to the concepts of the present invention;

FIG. 13 is another perspective view of the line-holding mechanism ofFIG. 12;

FIG. 14 is a side elevational, sectional view of the line-holdingmechanism of FIG. 12, having a strip of line loaded therein;

FIG. 15 is a perspective view of a fifth embodiment of a line-holdingmechanism according to the concepts of the present invention;

FIG. 16 is cross-sectional view of the line-holding mechanism of FIG. 15taken along the line A-A in FIG. 15;

FIG. 17 is a perspective view of the line-holding mechanism of FIG. 15,having a strip of line loaded therein; and

FIG. 18 is another perspective view of the line-holding mechanism ofFIG. 15, having a strip of line loaded therein.

DETAILED DESCRIPTION

As noted above, the trimmer head of the present invention is a“fixed-line” trimmer head of the type having a line-holding mechanismthat is typically to be utilized for holding a folded strip of trimmerline in a manner such that both ends of the folded strip of trimmer lineimpacts and cuts vegetation. However, it has been found that using bothends of a folded strip of trimmer line to impact and cut vegetation isredundant is some instances (i.e., the vegetation is already cut by thefirst end of the folded trimmer line by the time the second end of thefolded trimmer line can cut the vegetation), and causes drag on thetrimmer head, due to the number of extended length ends of trimmer line(i.e., two for each folded strip of trimmer line) used in cutting thevegetation. In order to reduce the drag of the trimmer line on thetrimmer head, the present invention seeks to reduce the number ofextended length ends of trimmer line used. To do so however, the foldedstrips of trimmer line cannot extend from its line-holding mechanismwith equal extended length ends, as is currently the case. Instead, thepresent invention provides for a line-holding mechanism adapted to holda single strip of line wherein one end of the strip of line is ofextended length so as to extend beyond the periphery of the trimmer headto impact and cut vegetation, while the other end of the strip of lineis not of extended length and is sufficiently short so as not to extendbeyond the periphery of the trimmer head to impact and cut vegetation.

While one might envision the prior art line-holding mechanisms beingable to provide one extended and one short end for the folded strips ofline, there is no such folded strips of line currently available on themarket, and further use of a single strip of line that does not provideequal extended lengths of line extending from the line-holdingmechanisms of the prior art could easily pull the line out of thecurrent versions of the line-holding mechanisms due to the fact that themechanisms have parallel, straight through line channels in eachline-holding mechanism. These line channels were made for use withfolded strips of line of approximately equal length ends. If the endlengths of the folded strips of line are not of equal lengths, then itis common for the shorter length end of the strip of line to be pulledback through its entrance and for the strip of line to be disengagedfrom the line-holding mechanism altogether. As such, the trimmer head ofthe present invention is believed to be a significant improvement overthe trimmer head disclosed and taught by Jerez, in U.S. Pat. Nos.7,743,511 and 7,603,782 (hereinafter “Jerez”), the disclosure of whichis incorporated herein by reference.

In order to provide a full understanding of the present invention, it isbelieved necessary to provide a description of a prior art embodiment ofa “fixed-type” trimmer line of the type typically employed for holdingand using folded strips of line to impact and cut vegetation. Therefore,a trimmer head representing a current commercial embodiment of the priorart as taught by Jerez is referred to generally by the numeral 10 inFIG. 1, and is operably attachable to a rotary trimmer device (notshown) utilizing conventional means. For example, in the embodimentshown, a central threaded stem (not shown) on a conventional trimmerdevice (not shown) is passed through the central opening 11 in axialalignment with the axis of rotation (X) for the trimmer head andconnected by a fastener (not shown), such as a hex bolt and nut. It willbe appreciated that the trimmer head may be connected or otherwiseattached to the rotary trimmer device by any manner known in the art.

As shown in FIG. 1, the trimmer head 10 includes a housing 12 defined bya upper portion or cover 14 and a bottom portion or main housing 16,both of which extend radially outward from a center axis of rotationidentified by the broken line X. The upper and lower portions 14 and 16form a relatively flat housing 12 having a periphery 18 and are heldtogether, in this embodiment, by a plurality of screws 19. The upperportion further includes a plurality of openings 20 defined within theupper portion and spaced from the periphery 18 of the housing 12.

In this embodiment of the trimmer head 10, there are three sections orlegs, extending approximately 120° apart, wherein each leg 22 includesone opening 20 for receiving one line-holding mechanism 30. It will beappreciated that the trimmer head 10 can be of any configuration knownin the art and can typically have from 2 to 6 openings, and morepreferably 3, 4 or 5 openings 20 for receiving the line-holdingmechanisms 30 therethrough. Essentially, the line-holding mechanisms 30are radially spaced apart so as to provide balance to the trimmer headduring rotation.

As more particularly detailed in FIGS. 2 and 3, the line-holdingmechanism 30 of the prior art generally consists of a plastic (e.g.,glass filled nylon) molded post portion 32 with a flange 34 on the lowerend and two parallel line channels 36 proximate the upper end of thepost portion 32, wherein a portion of the plastic separates the two linechannels 36. It will be appreciated that the flange 34 is sandwichedbetween the upper portion 14 and lower portion 16 to prevent thevertical movement of the mechanism 30. However, the mechanism 30 is notprevented from rotating freely about a vertical axis defined by thebroken line Z. More particularly, it will be appreciated that a metalring (not shown) is press fit into each of the openings 20, which metalring acts as a bearing sleeve. Because of the metal ring/bearing sleeve,the mechanism 30 is constrained from all movement other than pivotingrotational movement around vertical axis Z when disposed with thetrimmer head.

The two parallel line channels 36, 36 a are molded into the plastic ofthe post portion to define two parallel, straight-through passageways38, 38 a extending from one side of the post portion to the other side.In the embodiment shown, the post portion 32 includes two beveledsurfaces 40 on opposite sides of the post portion 32 on which aredisposed the entrances 42 and exits 44 of the line channels 36 such thatthe beveled surfaces 40 provide for longer lengths of the line channels36 near the bottom of the line channels and shorter lengths for the linechannels 36 near the top of the line channels. In other words, bothbeveled surfaces slant upwards toward the center of the top end of thepost portion 32.

To load the prior art line-holding mechanism 30, one of the two opposingends of a folded strip of line (not shown) is inserted into or threadedthrough one of the respective straight passageways 38 defined by one ofthe respective line channels 36 at its entrance 42 and out its exit 44,while the other opposing end of the folded strip of line is,simultaneously or in series, inserted into or threaded through the otherof the respective straight passageways 38 at its entrance 42 and out itsexit 44, until the central folded portion of the strip of line is pulledtightly against the portion 46 of the plastic separating the two linechannels 36. Once, fully inserted, the mechanism 30 holds the foldedstrip of trimmer line in place by centrifugal force during rotation.

The present invention provides for essentially the same trimmer head andhousing with openings for receiving line-holding mechanisms as the priorart discussed above. However, the present invention differssignificantly with respect to the design of the line holding mechanisms.Accordingly, the drawings and discussion henceforth will besubstantially directed to different embodiments of the new line-holdingmechanisms according to the concepts of the present invention. Where anyrecitations to the trimmer head or component parts other than thosedisposed as a part of the line-holding mechanism are discussed, the samenumerals as used above will be set forth.

A first embodiment of a line-holding mechanism according to the conceptsof the present invention is shown generally by the numeral 50 in FIGS.4-6. This line-holding mechanism 50 includes a post portion 52 and aflange 54 which operate essentially as described above for theline-holding mechanisms 30 of the prior art. The flange 54 is disposedat one end of the post portion 52 and extends beyond the periphery ofthe post portion 52.

The post portion 52 includes two curved, unobstructed line channels 56,56 a, each of which defines a passageway 58, 58 a adapted to receive astrip of line. By the term “unobstructed” as used throughout this paper,it is meant that the line channels do not have any obstructions such asclamping mechanisms or other holding elements within the channels to aidin holding the strip of line to the mechanism. It will be appreciatedthat the line channels and passageways of all of the embodiments of thisinvention are clear and completely free from elements that may obstructor aid the mechanism for holding the line.

In this first embodiment, both line channels 56, 56 a are transverse tothe vertical axis (Z) of the mechanism 50 and are curved such that anyportion of the strip of line capable of being received through thepassageway 58, 58 a of the respective line channel 56, 56 a is bent atthat portion of the strip of line away from the other line channel whilepassing through its line channel. Both line channels 56, 56 a have anentrance 60, 60 a and an exit 62, 62 a. In this embodiment, the entrance60 of one line channel 56 faces opposite the exit 62 a of the other linechannel 56 a. The exit 62 of the one line channel 56 is adjacent to theentrance 60 a of the other line channel 56 a, while the exit 62 of theone line channel 56 is proximate to its entrance 60 and the entrance 60a of the other line channel 56 a is proximate to its exit 62 a.

To load the strip of line, it will be appreciated that the line 64 isfirst inserted into the first line channel 56 at entrance 60 and ispushed through the curved passageway 58 to the respective exit 62. Theline is then “folded” and pushed into the second line channel 56 a atits entrance 60 a adjacent to the exit 62, whereupon it is disposedthrough the curved passageway 58 a to the respective exit 62 a. It willbe appreciated that the resultant strip of line will be shaped with akink or fold 66 near one end thereof, with the opposing ends 68, 69 ofthe strip of line pointing in opposite directions (see FIG. 6).Accordingly, it will be appreciated that, because the ends of the lineare pointed in opposite directions, it is impossible to have equallength portions of line extending from the line-holding mechanism 50.Otherwise, the line would be hitting the central stem of the rotarytrimmer device when pivoting about the axis Z. Consequently, it isrequired that one end of the line be shorter than the other. As such,one end of the line is of a length sufficient to extend beyond theperiphery of the trimmer head to impact and cut vegetation, while theother end of the line is positioned close to the post portion and is ofa length short enough to not extend beyond the periphery of the trimmerhead and does not impact or cut vegetation. As noted above, anywherefrom 2 to 6 mechanisms 50 can be spaced apart on the trimmer head 10,but only one line per mechanism extends to cut the vegetation, therebyproviding less drag due to fewer ends of the strips of line beingextended beyond the trimmer head to cut vegetation.

A second embodiment of a line-holding mechanism according to theconcepts of the present invention is shown generally by the numeral 70in FIGS. 7-8. This line-holding mechanism 70 includes a post portion 72and a flange 74 which operate essentially as described above for theline-holding mechanisms 30 of the prior art. The flange 74 is disposedat one end of the post portion 72 and extends beyond the periphery ofthe post portion 72.

The post portion 72 includes two curved, unobstructed line channels 76,76 a, each of which defines a passageway 78, 78 a adapted to receive astrip of line. In this second embodiment, both line channels 76, 76 aare parallel to the vertical axis (Z) of the mechanism 70 and are curvedsuch that any portion of the strip of line capable of being receivedthrough the passageway 78, 78 a of the respective line channel 76, 76 ais bent at that portion of the strip of line away from the other linechannel while passing through its line channel. Both line channels 76,76 a have an entrance 80, 80 a and an exit 82, 82 a. In this embodiment,the entrance 80 of one line channel 76 faces opposite the exit 82 a ofthe other line channel 76 a. The exit 82 of the one line channel 76 isadjacent to the entrance 80 a of the other line channel 76 a, while theexit 82 of the one line channel 76 is proximate to its entrance 80 andthe entrance 80 a of the other line channel 76 a is proximate to itsexit 82 a.

To load the strip of line, it will be appreciated that the line 84 isfirst inserted into the first line channel 76 at entrance 80 and ispushed through the curved passageway 78 to the respective exit 82 at thetop of the post portion. The line is then “folded” and pushed down intothe second line channel 76 a at its entrance 80 a adjacent to the exit82, whereupon it is disposed through the curved passageway 78 a to therespective exit 82 a. It will be appreciated that the resultant strip ofline will be shaped with a kink or fold 86 near one end thereof, withthe opposing ends 88, 89 of the strip of line pointing in oppositedirections (see FIG. 8). Accordingly, it will be appreciated that,because the ends of the line are pointed in opposite directions, it isimpossible to have equal length portions of line extending from theline-holding mechanism 70. Otherwise, the line would be hitting thecentral stem of the rotary trimmer device when pivoting about the axisZ. Consequently, it is required that one end of the line be shorter thanthe other. As such, one end of the line is of a length sufficient toextend beyond the periphery of the trimmer head to impact and cutvegetation, while the other end of the line is positioned close to thepost portion and is of a length short enough to not extend beyond theperiphery of the trimmer head and does not impact or cut vegetation. Asnoted above, anywhere from 2 to 6 mechanisms 70 can be spaced apart onthe trimmer head 10, but only one line per mechanism extends to cut thevegetation, thereby providing less drag due to fewer ends of the stripsof line being extended beyond the trimmer head to cut vegetation.

A third embodiment of a line-holding mechanism according to the conceptsof the present invention is shown generally by the numeral 90 in FIGS.9-11. This line-holding mechanism 90 again includes a post portion 92and a flange 94 which operate essentially as described above for theline-holding mechanisms 30 of the prior art. The flange 94 is disposedat one end of the post portion 92 and extends beyond the periphery ofthe post portion 92.

In this embodiment, the post portion 92 includes one straightunobstructed line channel 96 and one curved, unobstructed line channel96 a. Each of line channels 96, 96 a defines a passageway 98, 98 aadapted to receive a strip of line. In this third embodiment, both linechannels 96, 96 a are transverse to the vertical axis (Z) of themechanism 90. However, only line channel 96 a is curved such that anyportion of the strip of line capable of being received through thepassageway 98 a of the respective line channel 96 a is bent at thatportion of the strip of line away from the other line channel whilepassing through the line channel. Both line channels 96, 96 a have anentrance 100, 100 a and an exit 102, 102 a. In this embodiment, theentrance 100 of the straight line channel 96 is substantiallyorthogonal, or at least not parallel to the exit 102 a of the curvedline channel 96 a. The exit 102 of the straight line channel 96 is stilladjacent to the entrance 100 a of the curved line channel 96 a, but theexit 102 of the straight line channel 96 is tangential to its entrance100, while the entrance 100 a of the curved line channel 96 a isproximate to its exit 102 a.

To load the strip of line, it will be appreciated that the line 104 isfirst inserted into the straight line channel 96 at entrance 100 and ispushed through the its straight passageway 98 to the respective exit102. The line is then “folded” and pushed into the second line channel96 a, which is curved, at its entrance 100 a adjacent to the exit 102,whereupon it is disposed through the curved passageway 98 a to therespective exit 102 a. It will be appreciated that the resultant stripof line will be shaped with a kink or fold 106 near one end thereof,with the opposing ends 108, 109 of the strip of line pointing insubstantially orthogonal, or at least not parallel directions (see FIGS.9 and 10). Accordingly, it will be appreciated that, because the ends ofthe line are pointed in non-parallel directions, it is extremelycomplicated, if not impossible, to have equal length portions of lineextending from the line-holding mechanism 90. Otherwise, the line wouldbe hitting the central stem of the rotary trimmer device when pivotingabout the axis Z. Consequently, it is required that one end of the linebe shorter than the other. As such, one end of the line is of a lengthsufficient to extend beyond the periphery of the trimmer head to impactand cut vegetation, while the other end of the line is positioned closeto the post portion and is of a length short enough to not extend beyondthe periphery of the trimmer head and does not impact or cut vegetation.As noted above, anywhere from 2 to 6 mechanisms 90 can be spaced aparton the trimmer head 10, but only one line per mechanism extends to cutthe vegetation, thereby providing less drag due to fewer ends of thestrips of line being extended beyond the trimmer head to cut vegetation.

A fourth embodiment of a line-holding mechanism according to theconcepts of the present invention is shown generally by the numeral 110in FIGS. 12-14. This line-holding mechanism 110 again includes a postportion 112 and a flange 114 which operate essentially as describedabove for the line-holding mechanisms 30 of the prior art. The flange114 is disposed at one end of the post portion 112 and extends beyondthe periphery of the post portion 112.

In this embodiment, the post portion 112 also includes one straightunobstructed line channel 116 and one curved, unobstructed line channel116 a. Each of line channels 116, 116 a defines a passageway 118, 118 aadapted to receive a strip of line. In this fourth embodiment, both linechannels 116, 116 a are parallel to the vertical axis (Z) of themechanism 110. However, only line channel 116 a is curved such that anyportion of the strip of line capable of being received through thepassageway 118 a of the respective line channel 116 a is bent at thatportion of the strip of line away from the other line channel whilepassing through the line channel. Both line channels 116, 116 a have anentrance 120, 120 a and an exit 122, 122 a. In this embodiment, theentrance 120 of the straight line channel 116 is substantiallyorthogonal, or at least not parallel to the exit 122 a of the curvedline channel 116 a. The exit 122 of the straight line channel 116 isstill adjacent to the entrance 120 a of the curved line channel 116 a,but the exit 122 of the straight line channel 116 is tangential to itsentrance 120, while the entrance 120 a of the curved line channel 116 ais proximate to its exit 122 a.

To load the strip of line, it will be appreciated that the line 124 isfirst inserted into the straight line channel 116 at entrance 120 and ispushed through the its straight passageway 118 to the respective exit122. The line is then “folded” upward and pushed into the second linechannel 116 a, which is curved, at its entrance 120 a adjacent to theexit 122, whereupon it is disposed through the curved passageway 118 ato the respective exit 122 a. It will be appreciated that the resultantstrip of line will be shaped with a kink or fold 126 near one endthereof, with the opposing ends 128, 129 of the strip of line pointingin substantially orthogonal, or at least not parallel directions (seeFIG. 14). Accordingly, it will be appreciated that, in this case, thesecond end 129 of the strip of line 124 is pointed in an upwardlydirection and as such, use of that end 129 of the line to cut vegetationis impossible. As such, one end of the line is of a length sufficient toextend beyond the periphery of the trimmer head to impact and cutvegetation, while the other end of the line is positioned close to thepost portion and is of a length short enough to not extend beyond theperiphery of the trimmer head and does not impact or cut vegetation. Asnoted above, anywhere from 2 to 6 mechanisms 110 can be spaced apart onthe trimmer head 10, but only one line per mechanism extends to cut thevegetation, thereby providing less drag due to fewer ends of the stripsof line being extended beyond the trimmer head to cut vegetation.

A fifth embodiment of a line-holding mechanism according to the conceptsof the present invention is shown generally by the numeral 130 in FIGS.15-18. This line-holding mechanism 130 again includes a post portion 132and a flange 134 which operate essentially as described above for theline-holding mechanisms 30 of the prior art. The flange 134 is disposedat one end of the post portion 132 and extends beyond the periphery ofthe post portion 132.

However, this embodiment differs from the other embodiments in that thepost portion 132 includes one straight unobstructed line channel 136 aand one straight, pie-shaped, line channel 136 that is obstructed by thefirst straight line channel 136. Each of the line channels 136, 136 adefines a passageway 138, 138 a adapted to receive a strip of line. Inthis fifth embodiment, the first line channel 136 is pie-shaped andobstructed by the second line channel 136 a. The pie shaped line channel136 is essentially parallel to the vertical axis (Z) of the mechanism130, while the straight line channel 136 a is essentially orthogonal ortransverse to the vertical axis (Z) of the mechanism 130.

Pie-shaped line channel 136 is unique in that it has an entrance 140that is also its exit, but it also has an elongated opening 141 oppositeits entrance 140 for folding the strip of line back into the sameopening 141. Straight line channel 136 is tangentially disposed straightthrough the post portion 132.

To load the strip of line, it will be appreciated that the line 144 isfirst inserted into the straight, pie-shaped line channel 136 at itsentrance 140 and is pushed through the its straight passageway 138 tothe opening 141. The line 144 will necessarily be inserted below orabove the obstructing straight line channel 136 a within the passageway138. Once through, the line may be folded or kinked upon its self andpushed back through opening 141, wherein the line 144 will be pushedover or under the obstructing line channel 136, whichever passageway isnot already taken by the line 144 during its first pass through thispassageway 138. Thus, the line forms a loop around the obstructing linechannel 136. Upon exiting the entrance 140, the line is then wrappedaround the post portion 132 to be inserted into the entrance 142 of linechannel 136 a, wherein it is then passed through the passageway 138 a ofthat line channel 136 a to an exit 143 on the other side of the postportion.

It will be appreciated that the resultant strip of line will be shapedwith a kink or fold 146 near one end 149 thereof, within opening 141around line channel 136 a. There will also be a portion 147 of the linethat is wrapped around the outside of the post portion 132 between theentrance 140 of the pie-shaped line channel 136 and the entrance 142 ofthe straight line channel 136 a. In essence, it will be appreciated thatthe opposing ends 148, 149 of the strip of line 144 will be pointing insubstantially orthogonal, or at least not parallel, directions (seeFIGS. 17 and 18). Accordingly, it will be appreciated that, because theends of the line are pointed in non-parallel directions, it is extremelycomplicated, if not impossible, to have equal length portions of lineextending from the line-holding mechanism 130. Otherwise, the line wouldbe hitting the central stem of the rotary trimmer device when pivotingabout the axis Z. Consequently, it is required that one end of the linebe shorter than the other. As such, one end of the line is of a lengthsufficient to extend beyond the periphery of the trimmer head to impactand cut vegetation, while the other end of the line is positioned closeto the post portion and is of a length short enough to not extend beyondthe periphery of the trimmer head and does not impact or cut vegetation.As noted above, anywhere from 2 to 6 mechanisms 130 can be spaced aparton the trimmer head 10, but only one line per mechanism extends to cutthe vegetation, thereby providing less drag due to fewer ends of thestrips of line being extended beyond the trimmer head to cut vegetation.

It will be appreciated that any of a number of variations of the designof the line channels can be provided. However, it will be appreciatedthat when at least one line channel is curved, the ends of the strip ofline will most likely not be parallel to each other and as such, willneed to have one end that is shorter than the other. Thus the inventionadvantageously provides for only one end of the strip of line being usedto cut vegetation.

Other variations are within the spirit of the present invention. Thus,while the invention is susceptible to various modifications andalternative constructions, certain illustrated embodiments thereof areshown in the drawings and has been described above in detail. It shouldbe understood, however, that there is no intention to limit theinvention to the specific form or forms disclosed, but on the contrary,the intention is to cover all modifications, alternative constructions,and equivalents falling within the spirit and scope of the invention, asdefined in the appended claims.

All references, including publications, patent applications, andpatents, cited herein are hereby incorporated by reference to the sameextent as if each reference were individually and specifically indicatedto be incorporated by reference and were set forth in its entiretyherein.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the invention (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. The terms “comprising,” “having,” “including,” and “containing”are to be construed as open-ended terms (i.e., meaning “including, butnot limited to,”) unless otherwise noted. The term “connected” is to beconstrued as partly or wholly contained within, attached to, or joinedtogether, even if there is something intervening. Recitation of rangesof values herein are merely intended to serve as a shorthand method ofreferring individually to each separate value falling within the range,unless otherwise indicated herein, and each separate value isincorporated into the specification as if it were individually recitedherein. All methods described herein can be performed in any suitableorder unless otherwise indicated herein or otherwise clearlycontradicted by context. The use of any and all examples, or exemplarylanguage (e.g., “such as”) provided herein, is intended merely to betterilluminate embodiments of the invention and does not pose a limitationon the scope of the invention unless otherwise claimed. No language inthe specification should be construed as indicating any non-claimedelement as essential to the practice of the invention.

It will be appreciated that more than one embodiments of the presentinvention are described herein, including the best mode known to theinventors for carrying out the invention. Variations of those preferredembodiments may become apparent to those of ordinary skill in the artupon reading the foregoing description. The inventors expect skilledartisans to employ such variations as appropriate, and the inventorsintend for the invention to be practiced otherwise than as specificallydescribed herein. Accordingly, this invention includes all modificationsand equivalents of the subject matter recited in the claims appendedhereto as permitted by applicable law. Moreover, any combination of theabove-described elements in all possible variations thereof isencompassed by the invention unless otherwise indicated herein orotherwise clearly contradicted by context.

What is claimed is:
 1. A fixed-line trimmer head for a rotary trimmerdevice to be utilized with two or more strips of line, the trimmer headcomprising: a housing operatively attachable to the rotary trimmerdevice, the housing being rotatable when in use around a central axis ofrotation and having a upper portion and a lower portion extendingradially from the central axis, the upper portion having a periphery,wherein the upper portion has a plurality of openings spaced from theperiphery; and a plurality of mechanisms, each mechanism being pivotablearound a vertical axis, adapted to hold a strip of line, and including apost portion disposed through one of the openings in the upper portionof the housing, and a flange disposed at one end of the post portion andsandwiched between the upper portion and lower portion to preventvertical movement of the mechanism, wherein the post portion includestwo unobstructed line channels, each line channel defining a passagewayadapted to receive the same strip of line, wherein at least one of theline channels is curved such that any portion of the strip of linecapable of being received through the passageway of that line channel isbent at that portion of the strip of line away from the second linechannel while passing through that at least one line channel that iscurved.
 2. The fixed-line trimmer head as claimed in claim 1, whereinone line channel is straight such that any portion of the strip of linecapable of being received through the passageway of that line channel isnot bent at that portion of the strip of line while passing through thatline channel.
 3. The fixed-line trimmer head as claimed in claim 2,wherein both line channels have an entrance and an exit, wherein theexit of the one line channel is adjacent to and parallel with theentrance of the other line channel, while the entrance of the one linechannel is spaced from and not parallel to the exit of the other linechannel.
 4. The fixed-line trimmer head as claimed in claim 3, whereinthe line channels are transverse to the vertical axis of the mechanism.5. The fixed-line trimmer head as claimed in claim 3, wherein the linechannels are parallel to the vertical axis of the mechanism.
 6. Thefixed-line trimmer head as claimed in claim 1, in combination with aplurality of strips of line adapted to cut vegetation, wherein eachstrip of line is held to the trimmer head by one of the plurality ofmechanisms and is received through all of the passageways defined by thetwo line channels on the mechanism; wherein one end of the strip of lineis distal from the mechanism and extends beyond the periphery of theupper portion of the housing of the trimmer head to cut vegetation,while the other end of the strip of line is proximate to the mechanismand does not extend beyond the periphery of the upper portion of thehousing of the trimmer head.
 7. A mechanism to be utilized for holding astrip of line, the mechanism comprising: a post portion; and a flangedisposed at one end of the post portion and extending beyond theperiphery of the post portion, wherein the post portion includes twounobstructed line channels, each line channel defining a passagewayadapted to receive the strip of line, wherein at least one of the linechannels is curved such that any portion of the strip of line capable ofbeing received through the passageway of that line channel is bent atthat portion of the strip of line away from the second line channelwhile passing through the at least one line channel that is curved. 8.The mechanism as claimed in claim 7, wherein one line channel isstraight such that any portion of the strip of line capable of beingreceived by that line channel is not bent at that portion of the stripof line while passing through that line channel.
 9. The mechanism asclaimed in claim 8, wherein both line channels have an entrance and anexit, wherein the exit of the one line channel is adjacent to andparallel with the entrance of the other line channel, while the entranceof the one line channel is spaced from and not parallel to the exit ofthe other line channel